A variety of techniques and instrumentalities have been suggested heretofore for intimately associating an identification device of some type with a human subject to provide personal identification of the subject, his or her medical condition, etc. In recent years, an increasingly popular approach has contemplated the provision of such identifying data by the placement of a small information carrier, sometimes taking the form of a photographic microdot, in or on one of the subject's teeth. Prior teachings along this line are found in the following U.S. Pat. Nos.: Samis U.S. Pat. No. Re. 30,594 (originally U.S. Pat. No. 4,027,391), Muhlemann et al 4,208,795, Richardson 4,239,261, Mayclin 4,439,154, Michnick et al 4,512,744 and Elggren 4,557,693.
In those cases where a microdot is used as the identification carrier, prior identification techniques have contemplated that the microdot be read under magnification by an appropriate optical device. When the microdot is simply bonded to the surface of a subject's tooth, the reading process may require that the microdot be removed from the tooth, e.g., by a small chisel, before it is read under magnification. This technique has a number of disadvantages, e.g., the microdot can be removed by anyone improperly wishing to secrete a subject's identity, residual bonding agent tends to obscure or blur information contained in the microdot, and the microdot, once removed from the tooth, cannot be reused due to old bonding agent on the microdot. Prior techniques suggested heretofore wherein the identification carrier or microdot is actually imbedded within a tooth give rise to the still further problem of locating the actual position of the microdot or information carrier so that it can be removed from the tooth for reading.
In an effort to obviate some of the foregoing problems, various instrumentalities have been suggested heretofore for reading a microdot while it remains bonded to or embedded within a subject's tooth. In general, however, the instruments that have been suggested for such purposes are complex, costly, and require careful adjustment to assure that the information on a microdot is properly read. As a result, systems of this type have had limited appeal and have not gone into the widespread use which is required of a truly practical identification system.
The present invention is intended to obviate these disadvantages of the prior art by the provision of an improved dental identification system wherein a microdot is implanted into the tooth of a subject at a location which is predetermined, precise, and accurately repeatable from one to another subject, and wherein the information on a microdot so implanted is read, and a permanent record of the information obtained, by a comparatively inexpensive instrument, i.e., a camera employing a fixed focus lens, which does not require any adjustment or calibration at the time the microdot is read.